js 透過連結下載檔案

透過url單檔案下載, 並且解決a.download修改檔名不生效問題

/**
 * 透過url單檔案下載, 並且解決a.download修改檔名不生效問題
 * @param {String} url 檔案url
 * @param {String} filename 檔案自定義名稱
 * @returns Promise
 */

export function downloadFileByUrl(url, filename) {
    const x = new XMLHttpRequest()
    x.open('GET', url, true)
    x.responseType = 'blob'
    x.onload = () => {
        const url = window.URL.createObjectURL(x.response)
        const a = document.createElement('a')
        a.href = url
        a.target = '_blank'
        if (filename) {
            a.download = filename
        }
        a.click()
        a.remove()
    }
    x.send()
}